I tried with a moderately complex image [0] and it failed to properly remove anything.
Edit: saw matsemann's comment - I was using Firefox, where selecting areas and clicking remove did nothing. Tried Chrome and got the same result of progress bar and then broken image. Same result in Safari. All on MacOS.
Edit: saw matsemann's comment - I was using Firefox, where selecting areas and clicking remove did nothing. Tried Chrome and got the same result of progress bar and then broken image. Same result in Safari. All on MacOS.
[0] https://i.imgur.com/mbEnZYD.jpg